Subminiature snap action relay



N. F. LEO

SUBMINIATURE SNAP ACTION RELAY Feb. 28, 1967 4 Sheets-Sheet 2 Filed Oct. 22, 1965 I20. 2'74 4R1 34a N/cK F. L50

INVEN Q w mh AGENT Feb. 28, 1967 N. F. LEO 3,307,127

SUBMINIATURE SNAP ACTION RELAY Filed Oct. 22, 1965 4 Sheets-Sheet 5 53 N/cK in Lao 76 INVEN'TOR.

7d- 68 AGENT Feb. 28, 1967 N. F. LEO 3,307,127

SUBMINIATURE SNAP ACTION RELAY Filed Oct. 22, 1965 4 Sheets-Sheet 4 I64, 11(3 l e? 125 l(bl I24 i129 |23 us I34 154a 1 17 |5\ 1 I420 (43a 2 f Mk I3! I52 I42 NICK 3%. L50

INVENTOQ United States Fatent O f 3,307,127 SUBMINIATURE SNAP ACTION RELAY Nick F. Leo, 6058 Mary Ellen Ave., Van Nuys, Calif. 91401 Filed Oct. 22, 1965, Ser. No. 501,079 13 Claims. (Cl. 335-188) The invention set forth in this specification and the accompanying drawings pertains to electrical relays, and more particularly to multiple-pole, double-throw subminiature relays.

Subminiature relays are used in many rockets and spacecraft in which it is very important that the components be as small in size and light in weight as possible. In order to meet this requirement, one of the objects of the present invention is to supply a relay of the type described that is so designed both mechanically and electrically that the parts may be made very small without any impairment of function.

Another object is to provide a relay of the type described in which a relatively heavy current may be controlled by a comparatively feeble current.

A further object is to provide a relay of the type described that is very rugged despite its miniature size.

An additional object is to provide a relay of the type described in which the parts are so arranged and designed that the entire relay need be no larger than the first joint of a womans index finger.

Another object is to provide an actuating lever system that may be operated by a comparatively heavy spring, the design of the lever system being such that the tension of the spring may be overcome by the magnetic field of a very small electromagnet operated by a comparatively weak current.

A further object is to provide a lever system that will permit the contact making parts of either a single-pole double-throw relay or a double-pole double-throw relay to be moved through a distance several times as great as the distance between the pole piece of the electromagnet and the plate through which the magnetic circuit is completed, in order to make itsoperation less critical and to permit the safe control of heavier currents than would otherwise be feasible.

An additional object is to provide a relay of the type described in which the contacts are both opened and closed with a snap action.

Yet another object is to provide a relay in which the snap action spring serves to keep certain of the contacts closed excepting when the coil is energized.

Still another object is to provide a fail-safe relay in which both the snap action spring and the conventional keeper spring act together to keep the same contacts closed excepting when the coil is energized, and in which the normal action of either or both springs can be overcome only by the energizing of the coil.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of an illustrative embodiment. For this purpose, such an embodiment is shown in the drawings acompany-ing and forming part of the present specification. This embodiment will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

In the drawings:

FIGURE 1 is a side elevation of the relay, partly broken away to illustrate the structure more clearly;

FIG. 2 is a left end view of the structure shown in FIG. 1;

3,307,127 Patented Feb. 28, 1967 FIG. 3 is a top view of the structure shown in FIGS. 1 and 2;

FIG. 4 is a section taken on line 4-4 of FIG. 1;

FIG. 5 is an isometric view, partly broken away, of the structure shown in FIG. 1;

FIG. 6 is a section taken on line 66 of FIG. 1;

FIG. 7 is a section taken on line 77 of FIG. 1;

FIG. 8 is a section taken on line 8 8 of FIG. 1;

FIG. 9 is a section taken on line 99 of FIG. 1;

FIG. 10 is a section taken on line 10-10 of FIG. 1;

FIG. 11 is a section taken on line 1111 of FIG. 1;

FIG. 12 is a view similar to FIG. 1, illustrating a different species of the invention;

FIG. 13 is a left end view of the structure of FIG. 12, taken on line 1313 of FIG. 12; and

FIG. 14 is a section taken on line 1414 of FIG. 12.

The structure herein set forth is applicable to singlepole and double-pole relays having either single-throw or double-throw action. The illustrative embodiment shown in the figures, however, is of the double-pole, double-throw type having two identical poles or reeds 13 and 13a, FIG. 4. Reed 13 and the elements that cooperate therewith are best seen in FIGS. 1 and 5. Fixed contacts 11 and 12 are engageable respectively by the contact buttons 26 and 27 secured to the free end of the reed or pole 13. Inasmuch as the fixed contacts associated with pole 13a are identical to those associated with pole 13, a description of the latter and its cooperating contacts will suffice for both. Contact 11 resembles a foot extending to the left from member 61 which is anchored in an insulating block 49 appropriately secured within the main supporting frame 30; and the contact 12, as it is oriented in FIGS. 1 and 5, is an integral foot extending to the right from member 62 which, like member 61, is also anchored in the insulating block 49. Members 61 and 62 have enlarged heads 24 and 25 to facilitate the connection of conductors, as shown in FIG. 3.

The reed or pole 13 which bears the cont-act buttons 26 and 27 near its outer or free end, is pivotally carried in a manner hereinafter to be explained on the upturned forward end 38, FIGS. 1, 5 and- 6, of the actuating lever 14 whose other end has lateral lugs 28, FIGS. 1, 2 and 5, that nest in the notches 20 just above the tails 21 in the mounting brackets 16 and 16a, FIGS. 1, 2 and 5. The actuating lever 14 is dished near its outer end 38 to form a convex undersurface 34 which bears against the head 43 on the free end of the arm 42, for purposes hereinafter to be described.

The reed 13 has an opening 37 therein whose front and rear sides are parallel, and in the presently preferred embodiment the front side is the narrower of the two. The forward end 38 of the reed-actuating lever 14 has side projections 36 that extend laterally across the rear portion of the opening 37 adjacent the reeds tail 71 which turns upward to form a trough 39, FIG. 5, for the side projections 36 of the reed-actuating lever 14. By means about to be explained, the reed 13 is urged forward so that its tail 71 bears against the under edges of the projections 36. This forward pressure is supplied by a generally U-shaped spring 15, preferably formed of beryllium copper. The loop in this spring lies below the opening 37 in the reed 13, and the two ends of the spring extend upward through the opening. The rear end of the spring is welded in a notch or hook 18 in the downwardly curving end of the anchor arm 17 which extends forward and downward from the upper portion of the mounting bracket 16. This bracket is secured to the insulating block 49 by a bolt, screw or rivet 22. The front end of the U-shaped spring 15 is reduced in Width to form shoulders 41 that engage the under surface of the reed 13 adjacent the opening 37, and the narrowed front end of the spring is curved down to form a hook 40 that overhangs the forward edge of the opening. This edge is thus gripped between the hook 4t) and the shoulders 41 of the spring that forces the reed forward against the lugs or projections 36 on the upturned end of the actuating lever 14 (FIGS. 5 and 4).

The U-shaped spring 15 is biased so that its forward end 40 (best seen in FIG. 5) presses the reed 13 downward, causing its tail 71 to bear down on the forward end of the actuating lever 14 whose vertical elevation controls the internal stresses within the U-shaped snap action spring 15 that causes its forward end to snap up or down. These internal stresses are altered by slight variations in the angle of the portion of the reed 13 that is gripped between the hook 40 and shoulders 41 of the spring 15. If the stresses in the spring 15 urge the free end of the reed 13 upward, the button 26 on its upper surface engages the upper stationary contact 11, but if the internal stresses of the spring are such that the forward end of the reed is urged downwardly, then the button 27 engages the lower stationary contact 12. The mechanism described up to this point is thus a single-pole double-throw switch operated by the internal stresses in the U-shaped snap spring, and these stresses are indirectly controlled :by the pressure exerted upon this concave undersurface by the glass head 43 by means of intervening instrumentalities hereinafter set forth.

Bead 43a mounted on rod 42a, FIG. 2, bears on the concave undersurface 34a, FIG. 4, of the actuating lever 14a that operates the reed or pole 13a which selectively engages the stationary contact 12a, FIG. 4, or a companion contact, not shown, that is the counterpart of the stationary contact 11 to which reference has already been made. The total mechanism thus far described is thus a double-pole, double-throw switch that becomes a double-pole, double-throw relay by virtue of the mechanical and electrical components now to be described.

These mechanical and electrical components are supported by the same frame 30 upon which the insulating blocks 49 and 49a are mounted. The frame 30 comprises two depending side pieces '31 and 31a, FIGS. 1, 5, 7 and 9, that indirectly carry a pivoted frame or armature 32 and a can 60 that houses and supports the coil 69. The

can 60 is welded or otherwise appropriately secured at 59 to the flared out ends 58 of the side pieces 31 and 31a.

Inasmuch as the can and its cap 68 are both a part of the magnetic circuit of the relay, they are both formed of magnetic material. The cap has a central opening 78, and is provided with a flange 73 adjacent an annular shoulder 74. A washer 75, formed of a non-magnetic metal, has an outside diameter that is the same as the shoulder-to-shoulder dimension of the cap. This washer has a central aperture 76 that slidably fits the periphery of the iron core 67. The washer 75 is coaxially disposed against the cap 68 so that its periphery is flush all around with the annular shoulder 73. The cap and washer, thus disposed, are welded together. The magnetic core, passing through the aperture 76 in the washer, is welded to the washer. This positions the enlarged head 67' of the core in the center of the hole 78 in the cap, leaving a gap or annular recess 77 around the head of the core. The coil 69 is wound on the core, or slipped over it, before the reduced end 79 of the core is inserted into the mating central recess in the bottom of the can.

The enlarged head 67 of the core is of course magnetically insulated from the encircling portion of the cap by the magnetically non-conductive washer that supports the head of the core. When the coil 69 is energized, the head 67 becomes one of the magnetic poles, and since the opposite end 78 of the core has an opposite polarity, this opposite polarity is transmitted through the can to the cap 68 which surrounds the head 67 of the core. The gap 77 surrounding this head is thus a gap in the magnetic circuit. This gap is bridged by the movable overhanging ferrous plate 33. This plate is integral with two parallel side bars 51 that extend at right angles from opposite side of the top portion of the plate, thus forming a structure which when viewed in the plane of the plate as seen in FIG. 1, is generally L-shaped.

The free ends 54 and 54a of bars 51 are offset at 50 toward each other, terminating in trunnion-like end portions 54 and 54a. A crossbar 52 extends across the top edges of side bars 51 and is. integrally secured thereto.

The armature structure 32 is pivotally mounted on a crosspin or rod 48 whose opposite ends extend through discs 76 and 70a secured respectively to the outer surfaces of the downwardly extending sections 31 and 31a of the main frame 30. The discs 70 overlie the openings 55 in the downwardly extending sides 3:1. In assembly, the discs 70 are adjustably movable over the openings 55 in order to position the pivot rod 48 at right angles to the depending sides 31 of the frame regardless of possible imprecise positions of the apertures 55 due to manufacturing variations. When the discs 70 and 71 are properly adjusted in position, they are rigidly secured to the depending sides 31 and 31a by copper brazing or equivalent means.

The insulating beads 43 and 43a to which reference has several times been made, and which are in constant engagement with the convex undersurfaces of the actuating levers 1'4 and 14a, are secured to the upper ends of the curved members 42 and 42a that are rigidly affixed to the plate 33. Beads 43 and 43a accordingly press upward when the structure 32 moves counterclockwise (as seen in FIGS. 1 and 5) and their pressure is relaxed when element 33 moves clockwise.

Counterclockwise movement of armature 32 is produced by the action of spring 47. The lower end of this spring is fastened to the projection 53 on the crossbar 52 of the pivoted armature structure 32. The upper end of the expansion spring 47 is hooked in an aperture that extends through the threaded pin 65, FIG. 7. This threaded pin 65 extends upward through the loop 63, FIGS. 7 and 8, formed on the 'free end of the small rod 45 that is integrally secured at 46 to the cross member 44 formed on the frame 30 and extending at right angles therefrom in the direction of the opposite side of the frame. A'nut 64 is'threaded on the upper end of the threaded pin 65. This nut 64 may be turned to the right or the left in order to increase or reduce the tension of the spring 47 that depends from the pin 65. The underside of the nut 64 of course overhangs the loop 63 and bears thereupon.

counterclockwise movement of armature 32 under action of spring 47 is limited by the engagement of buttons 26 and 26a (on the reeds 13 and 13a) with the stationary contacts 11 and 11a respectively. These contacts are thus normally closed.

Clockwise rotation of the main armature structure 32 against the action of spring 47 is effected by the energizing of coil 69. The magnetic flux produced by the current in this coil is handled in a very efficient manner by the coil 67, the can 60 with its cap 68, and the armature 32, which in the presently preferred embodiment is stamped and formed from iron. When the flux pulls the plate 33 toward the cap 68, it actually moves in a very oblique path due to the distance of the shaft 48 around which the plate is pivoted. As a consequence, the vertical distance through which the plate 3 3 and the actuating beads 43 and 43a are moved is much greater than the horizontal distance traversed by the plate 33 in moving toward or from the enlarged end of the core 67 in response to the energizing of the coil 69. The plate 33 thus remains very close to the cap 68 and core 67 at all times, permitting the magnetic pull upon the plate to be near its maximum intensity even when the plate is at its maximum distance from the cap 68 and the core 67.

As previously mentioned, the expansion spring 47, urging armature 32 in a counterclockwise direction, normally holds the beads 34 and 34a in such position that the contacts on the top sides of the reeds 13 and 13a are in firm engagement with the associated stationary contacts 11 and 11a. However, when the beads 34 and 34a move downward in response to the energizing of the coil, the rounded undersurfaces of the actuating levers 14 and 14a of course follow them because of the downward pressure indirectly exerted upon these levers by the reeds 13 and 13a by the normal downward pressure of the Ushaped leaf springs and 15a. When the actuating levers 14 and 14a have moved down far enough to bring the forward ends of armatures 13 and 13a to a position in which the attached forward ends of springs 15 and 15a are so disposed that the stresses within the springs change their direction, then these ends snap downward and cause the poles 13 and 13a to close against the associated lower stationary contacts The movement of these poles or reeds is thus actually produced by these springs, the downward movement of the beads merely permitting the reeds to move downward under action of the snap springs which oppose the action of the expansion spring. The snap springs hold the lower contacts closed excepting when the beads are at the upper extreme of their travel.

In most relays, the keeper springs that move the armatures away from the electromagnets are attached near the ends of the armatures very close to the cores of the magnets. Consequently, if the armatures or poles are to be moved by a very light current, the expansion or keeper springs must themselves be very light. This makes them very ditficult to adjust effectively. The present structure, however, applies the force of the expansion spring to what is in elfect a lever of the third class, and the spring 47 may therefore have a much stronger pull than does the opposing magnetic field. The force of the spring 47 is applied against a moment arm that is very short. The spring 47v may therefore be much stronger than ordinarily used in miniature relays and its adjustment is therefore much less critical.

After the adjusting nut 64 has been rotated to a point that produces the desired amount of tension in the spring 47, the nut may be fixed in its adjusted position in any desired manner, the presently preferred method being to coat the nut and the end of the screw with a suitable cement or adhesive, such as Glyptol.

The double-pole, double-throw relay hereinbefore described and shown in the drawings is of such efiiciency that the presently preferred embodiment, although no larger than the first joint of the average womans index finger, applies a pressure of from 15 to grams to its contacts and switches circuits carrying seven amperes with 28 volts applied to the coil.

The eight terminals 84 for the relay are mounted in a plate 29 from which they are insulated by glass sleeves surrounding the shanks of the terminals. The leads 80 and 81 of the coil 69 are soldered to the shanks of two of these terminals, and the remaining six terminals are connected to conductors leading from the heads 23, 24, 25, 23, 24' and 25' of the pins or bolts that extend through the insulating blocks 49 and 49a, FIGS. 1 and 3. The conductors connected to pin or bolt heads 23 and 23' of course supply the current to the poles or reeds, as the lower end of these bolts or pins serve to mount the brackets 16 and 16a that carry the actuating levers 14 and 14' whose other ends support the reeds or poles 13 and 13'.

As hereinbefore explained, the can 60 is rigidly at tached to the side pieces 31 and 31a of the frame 30.

The side piece 31 has an extension or tongue 56, FIG. 1, that nests in a recess 83 in the terminal plate 29, and the side 31a of the frame has a similar projection, not

shown, that nests in a recess similar to the recess 83 in the opposite side of the terminal plate. The tongue or extension 56 and its counterpart on the other side of the unit are both soldered or otherwise securely attached to the terminal plate The ends of the terminals are insulated from the frame of the relay and from the can 60 by a non-conducting sheet 57, FIGS. 1, 9 and 10, that is mounted adjacent the ends of the terminals.

FIGS. 12, 13 and 14 illustrate an embodiment of the invention in which the contact 126 (which is the counterpart of the contact 26 in the previously described embodiment) is never in engagement with the stationary contact 111 unless the coil 169 that operates the relay is energized. Since the relay, in the form illustrated, is a double-pole double-throw relay, the corresponding parts of the companion contact system will of course likewise not be closed excepting when the coil is energized. This provides a fail-sate construction.

It will be noted that the portions of the structure best seen in FIGS. 12 and 14 are so disposed and arranged that their operation in many respects is just opposite from that of the previously described embodiment. The armature 132 of this fail-safe form is urged in a clockwise direction by the spring 147 rather than in a counterclockwise direction as is done by the spring 47 in the figures previously described.

For convenience in comparing the two embodiments, the components in the instant arrangement have been given the same reference numerals as the corresponding parts in the previously described structure excepting that the numeral 1 has been added in front of those used in the previously discussed figures.

The armature 132 is pivoted on shaft 148, but the keeper spring is attached to the rockable armature on the side of the pivot opposite from the contacts that are to be closed rather than on the same side as in the last descirbed structure; and the plate 133, which is the counterpart of the previously discussed plate 33, is likewise on the side of the pivot opposite from the contacts that are closed by means of the insulating glass beads 143 and 143a. Plate 133 depends from the left end of the armature (as the device is oriented in FIGS. 12 and 14).

A lug 153 is integrally attached to the armature just above the plate 133. The expansion spring 147 is pivotally secured to this lug by means of an aperture therein, and a bracket extends to the left of the top portion of the main chassis or frame 130 to provide a mounting for the upper end of the spring 147. A threaded screw 165, which is the counterpart of screw 65 of previously described figures, extends downward through an appropriate aperture in the end of the bar 145. As in the case of its counterpart in the previously described embodiment, screw is provided with a through hole near its lower end to fasten the upper end of the spring 147, and the effective length of the spring is adjusted by means of the nut 164 in a manner that will be clear from the discussion of the previous disclosure.

The side bars 151 and 151a of the armature 132 are tied together and strengthened by means of a crossplate 152 which is of course the equivalent of the bar 52 shown in FIG. 9.

The insulating beads 143 and 143a are mounted on the external ends of rods 142 and 142a, respectively, and the function of these components is the same as those with corresponding identifying characters in the previously discussed arrangement. In the present form, however, the beads press upward instead of downward when the coil is energized, and they are held in their lowermost position through the action of the spring 147.

As previously explained, the beryllium copper spring urges both ends of the reed (113 in this embodiment) down, and it will be clear that the application of the force of the spring 147 on the opposite side of the armature pivot from that on which it was mounted in the previously described embodiment, enables it to combine its force with that of the leaf spring 115 in keeping the contacts 126 and 111 out of engagement. Should spring 147 fail, the action of spring 115 alone will keep these contacts open.

When coil 169 is energized, the plate 133 is attracted by the enlarged end 167' of the magnet core, causing the insulating beads 143 and 143' to press upward against the convex underportions of the actuating lever, bead 143 being shown in such engagement with the convex undersurface 134 of the actuating lever 114 in FIG. 12.

When the coil is de-energized, the upward pull of spring 147 on the left end of the armature 132 causes the insulating beads to drop to their lower positions, and the convex underportions of the actuating levers will of course follow them due to the downward pressure constantly exerted by the spring 115, excepting, of course, when the end 171 of the reed has been raised to a high enough position to cause the internal stresses within the spring 115 to flip the free end of the reed upward to close the contacts 126 and 111. As long as the coil is energized, the lower contact 127 on the reed 113 remains in engagement with the stationary contact 112.

The insulating terminal plate 129 in this embodiment has been moved to the opposite end of the relay structure, and a depending leg has been added to the right end of both sides of the frame 130 to provide a suitable support for the terminal plate. This is effected by means of the projection 156 on the right side of the depending leg 231. This projection may nest in a recess in the edge of the plate 129 in a manner similar to that provided for the previously described form of the device.

The upper ends 123, 124 and 125 of the pins or bolts that pass through the insulating blocks may of course be connected by means of suitable conductors to specific terminals 184, as in the embodiment previously described. The end 123 of the pin or bolt 122 carries the current to the actuating lever 114 by means of the bracket 116 to which both the bolt 122 and the actuating lever are secured.

Various and sundry modifications may obviously be made in the structure hereinbefore set forth and other components may be substituted for those shown and described, providing the substitute components serve the same function, or the same function plus additional functions; and parts may be changed in position or transposed-all without departing from the broad "spirit of the invention as succinictly set forth in the appended claims in which the term ferrous material is to be construed to include all magnetically responsive substances.

The inventor claims:

1. Ina relay, a combination including: a cylinder of ferrous material; a first closure of ferrous material extending across one end of said cylinder and integrally secured thereto; a second closure of ferrous material extending across the other end of said cylinder, said second closure having an opening therethrough; a core of ferrous material having one end secured to said first closure and extending through said cylinder; non-magnetic means supporting the other end of said core within said opening in spaced relationship thereto, said non-magnetic means at least indirectly carried by said cylinder; a coil of wire surrounding said core; an electrically non-conductive structure at least indirectly rigidly connected to said 7 cylinder but spaced therefrom; first and second spaced stationary electrical contacts supported by said non-conductive structure; an elongated conducting element so supported by said non-conductive structure for pivotal movement that its free end may selectively engage said stationary contacts; a shaft disposed exteriorally of said cylinder and extending transversely thereof; means secured to said cylinder for supporting said shaft; 2. generally L-shaped structure pivoted on said shaft and so disposed that its short arm extends across said second closure with its long arm parallel to said elongated cylinder but paced therefrom, at least a part of the short arm of said L-shaped structure being formed of ferrous material; a rigid member secured to said L-shaped structure and extending therefrom in a direction generally away from the short arm; said member disposed in a first position when the second arm is attracted toward said second closure and core when said coil is energized; resilient means having one end connected to said L-shaped structure at a location displaced from said shaft and its other end so immobolized with respect to said cylinder that the resilient means urges said L-shaped structure in such direction that said rigid member is yieldingly held in a second position; and means for moving said elongated element from engagement with said first stationary contact into engagement with said second stationary contact in response to the movement of said member from said first position to said second position and for moving the elongated element from engagement with said second stationary contact into engagement with said first stationary contact in response to the movement of said member from said second position to said first position.

2. The device described in claim 1 in which the means secured to the cylinder for supporting the shaft is a pair of spaced plates each having one end secured to the periphery of the cylinder, the plane of each plate being parallel to the axis of the cylinder, said plates having portions extending laterally thereof to support the nonconductive structure.

3. The device of claim 2 in which the generally L-shaped structure is supported between said plates by said shaft.

joined to the same end of the plate at opposite sides thereof.

6. The device of claim 5 in which a third bar extends between said two spaced bars near the pivoted end of the generally L-shaped structure to strengthen the structure and provide a support for one end of the resilient means whereby it may apply its tension to the long arm of the L-shaped structure in such position that the pivoted structure becomes a lever of the third class enabling a relatively weak magnetic force acting on the short arm of the L-shaped structure that depends from the end of the long arm to overcome the tension of a relatively strong resilient means.

7. The device of claim 4 in which said bracket has an aperture therein and in which there is an externally threaded pin attached to the proximal end of the spring, said pin extending through said aperature, there being an internally threaded member threadedly secured to said pin on the side of said bracket opposite from said spring, said internally threaded member bearing upon said bracket and acting according to the direction in which it is rotated to increase or decrease the tension of said spring.

8. The device of claim 4 in which said internally threaded member is fixed in adjusted position.

'9. The device of claim 1 in which said member has an insulating bead secured to theend thereof.

10. The device of claim 1 with the addition of duplicate sets of stationary contacts supported by said nonoonductive structure and in which a second elongated conducting element cooperates with the duplicate set of stationary contacts, there being an additional rigid member carried by said L-shaped structure and a second means associated with said second elongated conducting element for moving it in response to the movement of said additional rigid member.

11. The combination set forth in claim 1 with the addition of a terminal plate supporting a plurality of mutually insulated terminals, two of said terminals each electrically connected to a different end of'said coil, two

other of said terminals each electrically connected to a different one of said stationary contacts, and another terminal electrically connected to said elongated conducting element.

12. The combination set forth in claim 1 in which the means for moving the elongated element from one stationary contact to the other includes an actuating lever and a snap-action leaf spring that is immobilized at one end, the actuating lever acting in response to the movement of said rigid member to move the non-immobilized end of said snap-action spring to a position in which its internal stresses cause it to snap the element from engagement with one of said stationary contacts into firm engagement with the other.

13. The combination set forth in claim 12 with the addition of a second pair of stationary contacts, a second snap-action leaf spring that is immobilized at one end, a second actuating lever and a second rigid memher secured to the L-shaped structure, the second actuating lever acting in response to the movement of the second rigid member to move the non-immobilized end of the second snap-action spring to a position in Which its internal stresses cause it to snap the second element from engagement With one of said second pair of stationary contacts into firm engagement with the other contact of said second pair.

References Cited by the Examiner UNITED STATES PATENTS 2,529,375 11/1950 Clement ZOO-87 X 2,978,591 4/1961 Ringger 20087 X 3,033,957 5/1962 Dean ZOO-87 X BERRNARD A. GILHEANY, Primary Examiner. J. BAKER, Assistant Examiner. 

1. IN A RELAY, A COMBINATION INCLUDING: A CYLINDER OF FERROUS MATERIAL; A FIRST CLOSURE OF FERROUS MATERIAL EXTENDING ACROSS ONE END OF SAID CYLINDER AND INTEGRALLY SECURED THERETO; A SECOND CLOSURE OF FERROUS MATERIAL EXTENDING ACROSS THE OTHER END OF SAID CYLINDER, SAID SECOND CLOSURE HAVING AN OPENING THERETHROUGH; A CORE OF FERROUS MATERIAL HAVING ONE END SECURED TO SAID FIRST CLOSURE AND EXTENDING THROUGH SAID CYLINDER; NON-MAGNETIC MEANS SUPPORTING THE OTHER END OF SAID CORE WITHIN SAID OPENING IN SPACED RELATIONSHIP THERETO, SAID NON-MAGNETIC MEANS AT LEAST INDIRECTLY CARRIED BY SAID CYLINDER; A COIL OF WIRE SURROUNDING SAID CORE; AN ELECTRICALLY NON-CONDUCTIVE STRUCTURE AT LEAST INDIRECTLY RIGIDLY CONNECTED TO SAID CYLINDER BUT SPACED THEREFROM; FIRST AND SECOND SPACED STATIONARY ELECTRICAL CONTACTS SUPPORTED BY SAID NON-CONDUCTIVE STRUCTURE; AN ELONGATED CONDUCTING ELEMENT SO SUPPORTED BY SAID NON-CONDUCTIVE STRUCTURE FOR PIVOTAL MOVEMENT THAT ITS FREE END MAY SELECTIVELY ENGAGE SAID STATIONARY CONTACTS; A SHAFT DISPOSED EXTERIORALLY OF SAID CYLINDER AND EXTENDING TRANSVERSELY THEREOF; MEANS SECURED TO SAID CYLINDER FOR SUPPORTING SAID SHAFT; A GENERALLY L-SHAPED STRUCTURE PIVOTED ON SAID SHAFT AND SO DISPOSED THAT ITS SHORT ARM EXTENDS ACROSS SAID SECOND CLOSURE WITH ITS LONG ARM EXTENDS ACROSS SAID SECOND DER BUT PACED THEREFROM, AT LEAST A PART OF THE SHORT ARM 